Though Napa is known mostly for its Cabernet Sauvignon, and for rather run-of-the-mill Sauvignon Blanc, a wave of ambitious Napa Sauvignons is garnering praise in high places

I’VE BEEN TRAVELING to Napa Valley, Calif., for more than 20 years, but on my most recent trip I did something I’d never done: I tasted only Sauvignon Blanc. “I don’t think I’ve ever heard of anyone doing that before,” said Sam Kaplan, winemaker at Arkenstone Vineyards, one of the Sauvignon producers on my list.

That’s because, of course, Napa is famous for its Cabernets. And yet the time seemed propitious for this particular pilgrimage. I’d tasted some very good Napa Sauvignons and heard about several others. I wanted...